This invention relates to flame spray powders of cobalt-molybdenum mixed metal agglomerates and to a method for producing them.
Commonly assigned copending U.S. patent application Ser. No. 414,976, filed Nov. 12, 1973, now abandoned describes free flowing flame spray powders of particle agglomerates held together by an aqueous soluble metallic compound, such as ammonium tungstate or ammonium molybdate, which upon heating to moderate temperatures decomposes to base metal and harmless byproducts. The powders are produced by an agglomerating technique, preferably spray drying.
Such spray drying usually results in a product with wider than desired particle size range, necessitating recycling of out-of-size agglomerates by reslurrying to redissolve the binder and then spray drying again. This ability to recycle out-of-size agglomerates to produce more agglomerates within the desired range of particle size makes such processing economically feasible.
When mixed cobalt-molybdenum agglomerates are prepared, using cobalt and molybdenum or molybdenum alloy metal powders and the ammonium salt of molybdenum as a binder, the binding action is lost upon recycling of the out-sized agglomerates.